Nelson Ivan Del Valle-Nazario was arrested Thursday at his gym on Waters Avenue. At least one parent believes the allegations can't be true.

"He seemed like a friendly person. He was a friendly neighbor, I said hi to him," neighbor Laura Franco told FOX 13 News.

But deputies say they recorded him on the phone admitting to having sex with a 12-year-old student between March of 2015 and September of 2016. Some meetings happened at his gym, Undisputed Fitness, and some at his home a few miles away.

"You are in a position of authority, kids are going to respect you, kids are going to look up to you," Franco said.

Parents also looked up to him. Despite the allegations, Anna Florentis, who is seen in videos, training with him, won't believe he could do something like that.

"I can't imagine the phone call is accurate. Maybe there is a misinterpretation of something," Flroentis said. "This person is not the kind of person who could do something like that… I would be willing to bet my life on it."

Florentis, who said Nazario's colleagues asked her to speak for the gym, said the victim's parents had an axe to grind regarding a dispute over tutoring time. Florentis insists other parents shouldn't be scared of the gym.

“When he teaches them martial arts, it's not just about martial arts, it's about the whole package, having honor, loyalty, integrity, he has a value system," Florentis said.

But deputies have charged him with two counts of lewd and lascivious behavior, and said their case is rock-solid.

"I am in total shock. I don't have kids, but this is a neighborhood, there's a school two blocks from here," Laura Franco added.